Mistakenly, mistakingly

[D45ist]

Which is correct?

The department store mistakenly, mistakingly mailed the gift to me instead of the bride.

 

[bhaisahab]

Only 'mistakenly' is correct.

 

[Rover_KE]

D45ist, forget about 'mistakingly'. It's so rarely used that most people will think it's a mistake. (Click)

 

[emsr2d2]

Which is correct?

The department store mistakenly/mistakingly mailed the gift to me instead of the bride.

See above. If you're giving us a choice between two words, put a slash mark between them, not a comma.

 

[D45ist]

Can you explain why mistakingly is incorrect? Is it primarily because it's outdated?

 

[andrewg927]

Because no one is using it.

 

[D45ist]

So, it's not incorrect. It's just out of favor?

 

[emsr2d2]

It's so out of use/out of favour that when I read your post, I was going to reply saying "Mistakingly isn't a real word". I was surprised to see Rover's Ngram result though I wasn't surprised to see that it doesn't appear to have been used since 1900.